1. Field of Invention
The present invention relates to a system and method for automated position monitoring and tracking of an object by optical and mechanical means; in particular, scanning an object within a defined zone and utilizing computer-based image processing on a real time basis.
2. Discussion of Prior Art
Monitoring and tracking a laterally moving object is important in many applications. In certain applications, it is desirable to have a tracking device not only to locate the position of the object but also to monitor the movement of the object without any significant delay of information.
For example, many eye-tracking devices have been recently developed for eye surgery with lasers, in particular, for photo-refractive surgery. A typical photo-refractive surgery scans a UV laser beam on the surface of the cornea to sculpt the profile of the corneal outer surface, one layer at a time. In U.S. Pat. No. 6,179,422, a tracking device is described that employs two scanning beams to scan across a reference mark affixed on the object to be tracked.
U.S. Pat. No. 5,620,436 discloses the use of a video camera to monitor the eye movements and to determine the position of an aiming beam on the eye. U.S. Pat. No. 5,632,742 utilizes four projecting laser spots on the eye and uses a set of peak-and-hold circuits to determine the position of the eye. In these designs, a ring shaped reference is used for determining the eye position, and spatial stationary infrared beams are applied to illuminate the reference. Sophisticated imaging systems and electronics, such as a CCD camera or four peak-and-hold circuits, are implemented to determine the position of the reference. The ring shape reference area are practically either the limbus of the eye or the iris of the eye; and the whole ring is needed as the reference for determining the eye position.
Another eye tracking system using infrared light to illuminate the pupil of the eye has been announced by ISCAN, Inc. This system is described as using infrared light to illuminate the eye, with the system then retrieving positioning information to a variety of applications, as e.g. computer control through eye movement as well as for assisting the disabled patient.
Any of a number of techniques for locating objects can be readily adapted to locate the center of the eye. It has been found desirable to improve the effectiveness and accuracy of such localizing or position determining systems. That is, given an object locating system used in conjunction with an excimer laser system, it has been found desirable to provide means for enhancing the ability of such systems to accurately locate the center of the eye and also accurately aim of the pulsed excimer beam into the eye.
The disclosures of the aforementioned patents are incorporated herein in their entirety. While these devices fulfill their respective particular objectives and requirements, the prior art does not suggest the novel system for continuously and accurately monitoring or tracking the position and change of position of an object associated with the operational condition of a motor vehicle.